Australia, unlike South Africa for example, never fully developed a culture of continuous miner or bord and pillar mining for high production operations.
These methods are by and large anathema to the underground mining culture in Australia. This legacy is part of the reason roadway development rates in Australian longwall mines lags behind those of American operations.
A new venture called Thin Seam Mining Pty Ltd (TSM) could help change the perception of Australian coal miners. TSM has been set up by experienced American coal miners to explore opportunities for thin seam mining in Australia, using proven American mining methods, purpose built equipment, and experienced operators. The operation’s general manager Earl Cook spoke to ILN about the company’s first venture with Allied Coal.
TSM director and mining consultant, Larry Cook, has investigated the possibility of thin seam mining in Australia since 1998. Earlier this year Allied Coal Pty Ltd through managing director Steve Baldwin, contracted TSM to mine a 5 million tonnes deposit on the lease occupied by the Bellambi West (previously South Bulli) longwall mine, near Wollongong in New South Wales.
The deposit, situated partly below previous South Bulli workings, is in the 1.2m thick Balgownie seam. It is a working thickness that has been mined with varying degrees of success in Australia. Cook worked previously at the US Steel longwall operation Mine 50 in West Virginia, a mine that holds the world record for thin seam longwall production of 22,700 clean tonnes per day from a 1.2-meter seam.
The new mine will be a stand-alone operation called Gibson’s colliery with access gained by direct entrance into the escarpment, adjacent to an existing portal developed in the 1920s. Mining will be configured in a seven-entry layout, carried out by one continuous miner serviced by three shuttle cars. First development only will be carried out, with no subsequent pillar extraction, with each cut through at 18m centres.
Commenting on the differences between this approach and conventional development drivage in Australia, Earl Cook said the operations would stay in-seam in a 1.2m seam. “You have no longwall in Australia with gateroads of less than 1.8 to 2.0 meters,” he said.
Cook said one key to increasing development rates was to develop smaller pillars and to separate the mining and bolting processes. “With two or three entries [as is the typical Australian layout] there’s no place to go if the roofbolter is down. With seven entries the continuous miner can have seven plunges before it is affected by the roof bolter. In this business the only time you make money is when the carbide hits the coal.”
Another key area is to increase coal haulage. A Joy continuous miner will load a shuttle car in less than 30 seconds Cook said, but the main difference between a longwall and a continuous miner operation was that a longwall had continuous haulage. TSM’s CM/shuttle car configuration keeps the shuttle cars as close to possible to the continuous miner operations. Cook said shuttle cars would tram no more than 50m to pick up and unload coal.
Purpose-built and modified thin seam mining equipment has been brought into Australia and modified electrically to comply with statutory requirements. These include a Joy 14CM15 continuous miner, three 10SC32 Joy shuttle cars, NARCO rebuilt for thin seam application, and a 12 tonne capacity Stamler feeder breaker. The belt will be located in the centre entry to provide access from three sides for loading from three shuttle cars.
Other than purpose-built equipment and proven systems of work, TSM believe that experienced people and attitudes are key components. To this end, the company is bringing in twenty experienced underground US coal miners to operate the first section, to make up roughly half the total workforce of 40.
“The key is they know it can be done,” Cook said. “We won’t bring a single person who hasn’t mined 300m in a 24 hour period using a continuous miner. The miner operators and the roof-bolters have all worked in 1-1.5m thick seams. We don’t have to go into an existing mine and convince operators it’s possible.”
This ‘critical mass’ of skills and experience will transfer to the remainder of the Australian workforce, which would be chosen more for attitude than for skills, Cook added.
Equipment operators will be responsible for the maintenance of their own gear, part of the TSM philosophy of making people accountable and responsible.
Allied Coal project manager Ken Singer is helping to ensure a good start up through the development of a comprehensive Safety Management Plan and making sure that all Australian statutory requirements are being met, Cook said.
The company is setting itself ambitious goals and aims to deliver in 300m per day of drivage. In essence, TSM will use as the primary means of mining a method utilised in Australian coal mines for the purely utilitarian requirement of developing roadways. Mining is expected to begin at the end of October.
